JSON schema to GraphQL schema mismatch

I just started to make use of Realm applications. I have some fields in my collection which can be stored as either a string or null, a number or null, objectId or null. On the JSON schema I can use “anyOf” to map the different values but I get warnings when my GraphQL schema is generated. See attached warnings. I read somewhere that GraphQL only supports one bsonType from the JSON schema.

These fields with warnings are not available to query in my GraphQL. Since the GraphQL is autogenerated, how do I change my JSON schema for fields that can store a number or a string or an objectId and a null value?